Audio Playback Settings for Voice Interaction

ABSTRACT

Example techniques relate to voice interaction in an environment with a media playback system that is playing back audio content. In an example implementation, while playing back first audio in a given environment at a given loudness: a playback device (a) detects that an event is anticipated in the given environment, the event involving playback of second audio and (b) determines a loudness of background noise in the given environment, the background noise comprising ambient noise in the given environment. The playback device ducks the first audio in proportion to a difference between the given loudness of the first audio and the determined loudness of the background noise and plays back the ducked first audio concurrently with the second audio.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority under 35 U.S.C. § 120 to, and is acontinuation of, U.S. patent application Ser. No. 15/946,585, filed onApr. 5, 2018, entitled “Audio Playback Settings for Voice Interaction,”the contents of which are incorporated by reference herein in theirentirety.

This application claims priority under 35 U.S.C. § 120 to, and is acontinuation of, U.S. patent application Ser. No. 15/277,810, filed onSep. 27, 2016, entitled “Audio Playback Settings for Voice Interaction,”and issued as U.S. Pat. No. 9,942,678 on Apr. 20, 2018, the contents ofwhich are incorporated by reference herein in their entirety.

FIELD OF THE DISCLOSURE

The disclosure is related to consumer goods and, more particularly, tomethods, systems, products, features, services, and other elementsdirected to media playback or some aspect thereof.

BACKGROUND

Options for accessing and listening to digital audio in an out-loudsetting were limited until in 2003, when SONOS, Inc. filed for one ofits first patent applications, entitled “Method for Synchronizing AudioPlayback between Multiple Networked Devices,” and began offering a mediaplayback system for sale in 2005. The Sonos Wireless HiFi System enablespeople to experience music from many sources via one or more networkedplayback devices. Through a software control application installed on asmartphone, tablet, or computer, one can play what he or she wants inany room that has a networked playback device. Additionally, using thecontroller, for example, different songs can be streamed to each roomwith a playback device, rooms can be grouped together for synchronousplayback, or the same song can be heard in all rooms synchronously.

Given the ever growing interest in digital media, there continues to bea need to develop consumer-accessible technologies to further enhancethe listening experience.

BRIEF DESCRIPTION OF THE DRAWINGS

Features, aspects, and advantages of the presently disclosed technologymay be better understood with regard to the following description,appended claims, and accompanying drawings where:

FIG. 1 shows an example media playback system configuration in whichcertain embodiments may be practiced;

FIG. 2 shows a functional block diagram of an example playback device;

FIG. 3 shows a functional block diagram of an example control device;

FIG. 4 shows an example controller interface;

FIG. 5 shows an example plurality of network devices;

FIG. 6 shows a functional block diagram of an example network microphonedevice;

FIG. 7 shows a technique to duck audio, according to exampleimplementations;

FIG. 8 shows a chart illustrating ducking of audio content;

FIG. 9 shows a technique to compress audio, according to exampleimplementations;

FIG. 10 is a diagram illustrating ducking and compression of audiocontent; and

FIG. 11 shows a technique to equalize audio, according to exampleimplementations.

The drawings are for the purpose of illustrating example embodiments,but it is understood that the inventions are not limited to thearrangements and instrumentality shown in the drawings.

DETAILED DESCRIPTION I. Overview

Ambient noise may interfere with conversation between people. Forinstance, two people engaged in conversation in a crowded room may havedifficulty understanding one another over ambient noise from otherpeople in the room as well as other sources of sound (e.g., music orother audio content from an audio playback system). When spoken wordsare clearly audible over ambient noise, those spoken words can beconsidered to have a “good” signal-to-noise ratio (i.e., “good” enoughfor comprehension during a conversation).

Some voice services (e.g., Amazon® ALEXA®, Microsoft® CORTANA®, andApple® SIRI®, among others now commercially available or that becomeavailable in the future) may use spoken words as input for voicecontrol, search, and other operations. A networked microphone device(e.g., a wireless speaker, a smartphone, tablet, laptop computer, orother device) may include a microphone for detecting voice inputs and anetwork interface for querying a voice service with the voice input. Thevoice response may respond to the query with a response, which might bea spoken response played aloud by the networked microphone device viaone or more speakers. As with conversations between two people, arelatively high signal-to-noise ratio may facilitate a voice servicecomprehending a voice input (i.e., being able to effectively parse thespoken words of the voice input into a command) and also a usercomprehending a spoken response from a voice service over noise.

As noted above, various sources of sound may be considered noiserelative to the voice input. For instance, when music is being played ina given environment while a voice input is spoken in that sameenvironment, the music can be considered “noise” with respect to thevoice input. Other sources of sound may generate ambient (e.g.,background) noise while the voice input is spoken. Improving thesignal-to-noise ratio of the voice input relative to these differentsources of noise may improve comprehension of the voice input.

Improving the voice input-to-noise ratio may involve increasing thevolume of the voice input or decreasing the volume of the noise, suchthat the volume of the voice input relative to the noise is increased.The human voice typically covers a broad frequency spectrum. However,only relatively narrow frequency bands are necessary to understandspeech. The relatively narrow frequency bands include the fundamentalfrequencies (approximately 100 Hz for males and 180 Hz for females) andthe frequencies just above. Therefore, a “good” voice input-to-noiseratio within those relatively narrow frequency bands is often sufficientfor comprehension. This ratio does not necessarily need to be “good”across a broad frequency spectrum for the voice input to becomprehendible. These relatively narrow frequency bands can be referredto a speech bands.

Like the human voice, music typically covers a broad frequency spectrum.However, the relatively narrow frequency bands that drive speechcomprehension are not as important to music consumption. Rhythm, timbre,and other compositional factors of music can be preserved whenfrequencies within the music that correspond to the speech bands arecut. As such, when music is being played while a voice input is spokenor a spoken response is played back, frequencies of the musiccorresponding to the speech bands can be ducked (i.e., temporalityreduced in volume) to improve the relative volume of the voice input orspoken response within the speech bands to the music. This ducking mayimprove the signal-to-noise ratio without significantly compromising themusic playback (the “noise”).

One possible drawback to lowering the volume of the music within certainfrequency ranges is that the perceived loudness of the music as a wholeis reduced. However, an audio playback system may offset this reductionin perceived loudness by increasing the volume in other frequency bands(e.g., in all other frequencies outside the speech bands) while thevolume of the music in the speech bands is being cut.

Another possible drawback to lowering the volume of the music withincertain frequency ranges is that some of the lower-amplitude (relativelyquiet) detail in the music may drop below the noise floor (e.g., theambient noise). Similar to how speech can be difficult to understandover music and ambient noise, portions of the music might be difficultto understand over the noise floor (e.g., conversations between people,appliances, HVAC, outdoor noise such as traffic, among other possiblesources). Losing low-amplitude fine detail in the music below the noisefloor may impact enjoyment of the music.

In some implementations, the audio playback system may compress themusic to bring the low-amplitude fine detail above the noise floor. Theaudio playback system may measure the ambient noise level, whichrelative to the music might include human speech. Then, the music may becompressed to increase the level of the low-amplitude fine detail abovethe noise floor. While compression might not preserve all detail,compressing the music may preserve some low-amplitude fine detail thatwould have been otherwise inaudible over the noise floor.

As noted above, speech may be difficult to comprehend in the presence ofnoise (e.g., music playback or other ambient noise). As such, someexample techniques noted above may involve an audio playback systemducking music or other audio content to improve the signal-to-noiseratio of speech (e.g., voice inputs and spoken responses) relative tothis noise, which may render the speech more comprehendible. Moregenerally, music playback within an environment may make speech by twoor more people attempting a conversation difficult to understand. In anattempt to alleviate this issue, an audio playback system may apply anequalization that improves the signal-to-noise (i.e., speech-to-music)ratio. This equalization may cut frequencies of music within the speechbands (i.e., the fundamental frequencies and those slightly above). Theequalization may also boost frequencies outside the speech bands in anattempt to maintain the perceived loudness of the music when portions ofthe music within the speech bands are cut.

Since such an equalization changes the characteristics of the musicbeing played back, some users may prefer that this equalization is notalways applied. Rather, such users might prefer that the equalization isapplied when speech is present. Speech within a given environment mightinclude a conversation between two people in the environment, atelephone conversation between one person in the environment and otherperson somewhere else, speech from a voice-capable artificialintelligence (e.g. a spoken response from a voice service), among otherexamples. In some implementation, an audio playback system may includeone or more microphones to detect speech. Alternatively, the audioplayback system may use sensors to detect the number of people withinthe environment, which may indirectly indicate the presence of speech(i.e., the system may assume that the volume of speech within anenvironment increases with the number of possible speakers within thatenvironment). When speech is detected, the audio playback system mayapply the equalization to improve the signal-to-noise ratio of thespeech to noise.

Example techniques may involve improving signal-to-noise ratio of speechto noise, such as music. A first implementation may include a playbackdevice playing back first audio in a given environment at a givenloudness, and while playing back the first audio: (a) detecting that anevent is anticipated in the given environment, the event involvingplayback of second audio and (b) determining a loudness of backgroundnoise in the given environment, wherein the background noise comprisesambient noise in the given environment. The first implementation mayfurther include ducking the first audio in proportion to a differencebetween the given loudness of the first audio and the determinedloudness of the background noise. The first implementation may alsoinclude playing back the ducked first audio concurrently with the secondaudio.

A second implementation may include a playback device determining aloudness of first audio being played back by the playback device and aloudness of background noise in a given environment. The secondimplementation may also include determining whether a difference betweena loudness of the first audio and a given dynamic range is (a) less thana determined loudness of the background noise or (b) greater than thedetermined loudness of the background noise. When the determineddifference between the loudness of the ducked first audio and the givendynamic range is less than the determined loudness of the backgroundnoise, the second implementation may further include compressing thefirst audio to a dynamic range that is louder than the determinedloudness of the background noise and playing back the compressed firstaudio. When the determined difference between the loudness of the firstaudio and the given dynamic range is greater than the determinedloudness of the background noise, the second implementation may includeplaying back the first audio without compression.

A third implementation may involve a playback device playing audiocontent. While playing audio, the playback device may detect that asignal-to-noise ratio in the given environment is below a speechthreshold. While the signal-to-noise ratio in the given environment isbelow a speech threshold, the playback device may apply an equalizationto the audio content. The equalization may cut certain frequency bandscorresponding to human speech. The equalization may also boost otherfrequency bands not corresponding to human speech.

Each of the these example implementations may be embodied as a method, adevice configured to carry out the implementation, a system of devicesconfigured to carry out the implementation, or a non-transitorycomputer-readable medium containing instructions that are executable byone or more processors to carry out the implementation, among otherexamples. It will be understood by one of ordinary skill in the art thatthis disclosure includes numerous other embodiments, includingcombinations of the example features described herein. Further, anyexample operation described as being performed by a given device toillustrate a technique may be performed by any suitable devices,including the devices described herein. Yet further, any device maycause another device to perform any of the operations described herein.

While some examples described herein may refer to functions performed bygiven actors such as “users” and/or other entities, it should beunderstood that this description is for purposes of explanation only.The claims should not be interpreted to require action by any suchexample actor unless explicitly required by the language of the claimsthemselves.

II. Example Operating Environment

FIG. 1 illustrates an example configuration of a media playback system100 in which one or more embodiments disclosed herein may be practicedor implemented. The media playback system 100 as shown is associatedwith an example home environment having several rooms and spaces, suchas for example, a master bedroom, an office, a dining room, and a livingroom. As shown in the example of FIG. 1 , the media playback system 100includes playback devices 102, 104, 106, 108, 110, 112, 114, 116, 118,120, 122, 124, control devices 126 and 128, a wired or wireless networkrouter 130, and a networked microphone device 132.

Further discussions relating to the different components of the examplemedia playback system 100 and how the different components may interactto provide a user with a media experience may be found in the followingsections. While discussions herein may generally refer to the examplemedia playback system 100, technologies described herein are not limitedto applications within, among other things, the home environment asshown in FIG. 1 . For instance, the technologies described herein may beuseful in environments where multi-zone audio may be desired, such as,for example, a commercial setting like a restaurant, mall or airport, avehicle like a sports utility vehicle (SUV), bus or car, a ship or boat,an airplane, and so on.

a. Example Playback Devices

FIG. 2 shows a functional block diagram of an example playback device200 that may be configured to be one or more of the playback devices102-124 of the media playback system 100 of FIG. 1 . The playback device200 may include a processor 202, software components 204, memory 206,audio processing components 208, audio amplifier(s) 210, speaker(s) 212,and a network interface 214 including wireless interface(s) 216 andwired interface(s) 218. In one case, the playback device 200 may notinclude the speaker(s) 212, but rather a speaker interface forconnecting the playback device 200 to external speakers. In anothercase, the playback device 200 may include neither the speaker(s) 212 northe audio amplifier(s) 210, but rather an audio interface for connectingthe playback device 200 to an external audio amplifier or audio-visualreceiver.

In one example, the processor 202 may be a clock-driven computingcomponent configured to process input data according to instructionsstored in the memory 206. The memory 206 may be a tangiblecomputer-readable medium configured to store instructions executable bythe processor 202. For instance, the memory 206 may be data storage thatcan be loaded with one or more of the software components 204 executableby the processor 202 to achieve certain functions. In one example, thefunctions may involve the playback device 200 retrieving audio data froman audio source or another playback device. In another example, thefunctions may involve the playback device 200 sending audio data toanother device or playback device on a network. In yet another example,the functions may involve pairing of the playback device 200 with one ormore playback devices to create a multi-channel audio environment.

Certain functions may involve the playback device 200 synchronizingplayback of audio content with one or more other playback devices.During synchronous playback, a listener will preferably not be able toperceive time-delay differences between playback of the audio content bythe playback device 200 and the one or more other playback devices. U.S.Pat. No. 8,234,395 entitled, “System and method for synchronizingoperations among a plurality of independently clocked digital dataprocessing devices,” which is hereby incorporated by reference, providesin more detail some examples for audio playback synchronization amongplayback devices.

The memory 206 may further be configured to store data associated withthe playback device 200, such as one or more zones and/or zone groupsthe playback device 200 is a part of, audio sources accessible by theplayback device 200, or a playback queue that the playback device 200(or some other playback device) may be associated with. The data may bestored as one or more state variables that are periodically updated andused to describe the state of the playback device 200. The memory 206may also include the data associated with the state of the other devicesof the media system, and shared from time to time among the devices sothat one or more of the devices have the most recent data associatedwith the system. Other embodiments are also possible.

The audio processing components 208 may include one or moredigital-to-analog converters (DAC), an audio preprocessing component, anaudio enhancement component or a digital signal processor (DSP), and soon. In one embodiment, one or more of the audio processing components208 may be a subcomponent of the processor 202. In one example, audiocontent may be processed and/or intentionally altered by the audioprocessing components 208 to produce audio signals. The produced audiosignals may then be provided to the audio amplifier(s) 210 foramplification and playback through speaker(s) 212. Particularly, theaudio amplifier(s) 210 may include devices configured to amplify audiosignals to a level for driving one or more of the speakers 212. Thespeaker(s) 212 may include an individual transducer (e.g., a “driver”)or a complete speaker system involving an enclosure with one or moredrivers. A particular driver of the speaker(s) 212 may include, forexample, a subwoofer (e.g., for low frequencies), a mid-range driver(e.g., for middle frequencies), and/or a tweeter (e.g., for highfrequencies). In some cases, each transducer in the one or more speakers212 may be driven by an individual corresponding audio amplifier of theaudio amplifier(s) 210. In addition to producing analog signals forplayback by the playback device 200, the audio processing components 208may be configured to process audio content to be sent to one or moreother playback devices for playback.

Audio content to be processed and/or played back by the playback device200 may be received from an external source, such as via an audioline-in input connection (e.g., an auto-detecting 3.5 mm audio line-inconnection) or the network interface 214.

The network interface 214 may be configured to facilitate a data flowbetween the playback device 200 and one or more other devices on a datanetwork. As such, the playback device 200 may be configured to receiveaudio content over the data network from one or more other playbackdevices in communication with the playback device 200, network deviceswithin a local area network, or audio content sources over a wide areanetwork such as the Internet. In one example, the audio content andother signals transmitted and received by the playback device 200 may betransmitted in the form of digital packet data containing an InternetProtocol (IP)-based source address and IP-based destination addresses.In such a case, the network interface 214 may be configured to parse thedigital packet data such that the data destined for the playback device200 is properly received and processed by the playback device 200.

As shown, the network interface 214 may include wireless interface(s)216 and wired interface(s) 218. The wireless interface(s) 216 mayprovide network interface functions for the playback device 200 towirelessly communicate with other devices (e.g., other playbackdevice(s), speaker(s), receiver(s), network device(s), control device(s)within a data network the playback device 200 is associated with) inaccordance with a communication protocol (e.g., any wireless standardincluding IEEE 802.11a, 802.11b, 802.11g, 802.11n, 802.11ac, 802.15, 4Gmobile communication standard, and so on). The wired interface(s) 218may provide network interface functions for the playback device 200 tocommunicate over a wired connection with other devices in accordancewith a communication protocol (e.g., IEEE 802.3). While the networkinterface 214 shown in FIG. 2 includes both wireless interface(s) 216and wired interface(s) 218, the network interface 214 may in someembodiments include only wireless interface(s) or only wiredinterface(s).

In one example, the playback device 200 and one other playback devicemay be paired to play two separate audio components of audio content.For instance, playback device 200 may be configured to play a leftchannel audio component, while the other playback device may beconfigured to play a right channel audio component, thereby producing orenhancing a stereo effect of the audio content. The paired playbackdevices (also referred to as “bonded playback devices”) may further playaudio content in synchrony with other playback devices.

In another example, the playback device 200 may be sonicallyconsolidated with one or more other playback devices to form a single,consolidated playback device. A consolidated playback device may beconfigured to process and reproduce sound differently than anunconsolidated playback device or playback devices that are paired,because a consolidated playback device may have additional speakerdrivers through which audio content may be rendered. For instance, ifthe playback device 200 is a playback device designed to render lowfrequency range audio content (i.e. a subwoofer), the playback device200 may be consolidated with a playback device designed to render fullfrequency range audio content. In such a case, the full frequency rangeplayback device, when consolidated with the low frequency playbackdevice 200, may be configured to render only the mid and high frequencycomponents of audio content, while the low frequency range playbackdevice 200 renders the low frequency component of the audio content. Theconsolidated playback device may further be paired with a singleplayback device or yet another consolidated playback device.

By way of illustration, SONOS, Inc. presently offers (or has offered)for sale certain playback devices including a “PLAY:1,” “PLAY:3,”“PLAY:5,” “PLAYBAR,” “CONNECT:AMP,” “CONNECT,” and “SUB.” Any otherpast, present, and/or future playback devices may additionally oralternatively be used to implement the playback devices of exampleembodiments disclosed herein. Additionally, it is understood that aplayback device is not limited to the example illustrated in FIG. 2 orto the SONOS product offerings. For example, a playback device mayinclude a wired or wireless headphone. In another example, a playbackdevice may include or interact with a docking station for personalmobile media playback devices. In yet another example, a playback devicemay be integral to another device or component such as a television, alighting fixture, or some other device for indoor or outdoor use.

b. Example Playback Zone Configurations

Referring back to the media playback system 100 of FIG. 1 , theenvironment may have one or more playback zones, each with one or moreplayback devices. The media playback system 100 may be established withone or more playback zones, after which one or more zones may be added,or removed to arrive at the example configuration shown in FIG. 1 . Eachzone may be given a name according to a different room or space such asan office, bathroom, master bedroom, bedroom, kitchen, dining room,living room, and/or balcony. In one case, a single playback zone mayinclude multiple rooms or spaces. In another case, a single room orspace may include multiple playback zones.

As shown in FIG. 1 , the balcony, dining room, kitchen, bathroom,office, and bedroom zones each have one playback device, while theliving room and master bedroom zones each have multiple playbackdevices. In the living room zone, playback devices 104, 106, 108, and110 may be configured to play audio content in synchrony as individualplayback devices, as one or more bonded playback devices, as one or moreconsolidated playback devices, or any combination thereof. Similarly, inthe case of the master bedroom, playback devices 122 and 124 may beconfigured to play audio content in synchrony as individual playbackdevices, as a bonded playback device, or as a consolidated playbackdevice.

In one example, one or more playback zones in the environment of FIG. 1may each be playing different audio content. For instance, the user maybe grilling in the balcony zone and listening to hip hop music beingplayed by the playback device 102 while another user may be preparingfood in the kitchen zone and listening to classical music being playedby the playback device 114. In another example, a playback zone may playthe same audio content in synchrony with another playback zone. Forinstance, the user may be in the office zone where the playback device118 is playing the same rock music that is being playing by playbackdevice 102 in the balcony zone. In such a case, playback devices 102 and118 may be playing the rock music in synchrony such that the user mayseamlessly (or at least substantially seamlessly) enjoy the audiocontent that is being played out-loud while moving between differentplayback zones. Synchronization among playback zones may be achieved ina manner similar to that of synchronization among playback devices, asdescribed in previously referenced U.S. Pat. No. 8,234,395.

As suggested above, the zone configurations of the media playback system100 may be dynamically modified, and in some embodiments, the mediaplayback system 100 supports numerous configurations. For instance, if auser physically moves one or more playback devices to or from a zone,the media playback system 100 may be reconfigured to accommodate thechange(s). For instance, if the user physically moves the playbackdevice 102 from the balcony zone to the office zone, the office zone maynow include both the playback device 118 and the playback device 102.The playback device 102 may be paired or grouped with the office zoneand/or renamed if so desired via a control device such as the controldevices 126 and 128. On the other hand, if the one or more playbackdevices are moved to a particular area in the home environment that isnot already a playback zone, a new playback zone may be created for theparticular area.

Further, different playback zones of the media playback system 100 maybe dynamically combined into zone groups or split up into individualplayback zones. For instance, the dining room zone and the kitchen zone114 may be combined into a zone group for a dinner party such thatplayback devices 112 and 114 may render audio content in synchrony. Onthe other hand, the living room zone may be split into a television zoneincluding playback device 104, and a listening zone including playbackdevices 106, 108, and 110, if the user wishes to listen to music in theliving room space while another user wishes to watch television.

c. Example Control Devices

FIG. 3 shows a functional block diagram of an example control device 300that may be configured to be one or both of the control devices 126 and128 of the media playback system 100. Control device 300 may also bereferred to as a controller 300. As shown, the control device 300 mayinclude a processor 302, memory 304, a network interface 306, and a userinterface 308. In one example, the control device 300 may be a dedicatedcontroller for the media playback system 100. In another example, thecontrol device 300 may be a network device on which media playbacksystem controller application software may be installed, such as forexample, an iPhone™, iPad™ or any other smart phone, tablet or networkdevice (e.g., a networked computer such as a PC or Mac™).

The processor 302 may be configured to perform functions relevant tofacilitating user access, control, and configuration of the mediaplayback system 100. The memory 304 may be configured to storeinstructions executable by the processor 302 to perform those functions.The memory 304 may also be configured to store the media playback systemcontroller application software and other data associated with the mediaplayback system 100 and the user.

In one example, the network interface 306 may be based on an industrystandard (e.g., infrared, radio, wired standards including IEEE 802.3,wireless standards including IEEE 802.11a, 802.11b, 802.11g, 802.11n,802.11ac, 802.15, 4G mobile communication standard, and so on). Thenetwork interface 306 may provide a means for the control device 300 tocommunicate with other devices in the media playback system 100. In oneexample, data and information (e.g., such as a state variable) may becommunicated between control device 300 and other devices via thenetwork interface 306. For instance, playback zone and zone groupconfigurations in the media playback system 100 may be received by thecontrol device 300 from a playback device or another network device, ortransmitted by the control device 300 to another playback device ornetwork device via the network interface 306. In some cases, the othernetwork device may be another control device.

Playback device control commands such as volume control and audioplayback control may also be communicated from the control device 300 toa playback device via the network interface 306. As suggested above,changes to configurations of the media playback system 100 may also beperformed by a user using the control device 300. The configurationchanges may include adding/removing one or more playback devices to/froma zone, adding/removing one or more zones to/from a zone group, forminga bonded or consolidated player, separating one or more playback devicesfrom a bonded or consolidated player, among others. Accordingly, thecontrol device 300 may sometimes be referred to as a controller, whetherthe control device 300 is a dedicated controller or a network device onwhich media playback system controller application software isinstalled.

The user interface 308 of the control device 300 may be configured tofacilitate user access and control of the media playback system 100, byproviding a controller interface such as the controller interface 400shown in FIG. 4 . The controller interface 400 includes a playbackcontrol region 410, a playback zone region 420, a playback status region430, a playback queue region 440, and an audio content sources region450. The user interface 400 as shown is just one example of a userinterface that may be provided on a network device such as the controldevice 300 of FIG. 3 (and/or the control devices 126 and 128 of FIG. 1 )and accessed by users to control a media playback system such as themedia playback system 100. Other user interfaces of varying formats,styles, and interactive sequences may alternatively be implemented onone or more network devices to provide comparable control access to amedia playback system.

The playback control region 410 may include selectable (e.g., by way oftouch or by using a cursor) icons to cause playback devices in aselected playback zone or zone group to play or pause, fast forward,rewind, skip to next, skip to previous, enter/exit shuffle mode,enter/exit repeat mode, enter/exit cross fade mode. The playback controlregion 410 may also include selectable icons to modify equalizationsettings, and playback volume, among other possibilities.

The playback zone region 420 may include representations of playbackzones within the media playback system 100. In some embodiments, thegraphical representations of playback zones may be selectable to bringup additional selectable icons to manage or configure the playback zonesin the media playback system, such as a creation of bonded zones,creation of zone groups, separation of zone groups, and renaming of zonegroups, among other possibilities.

For example, as shown, a “group” icon may be provided within each of thegraphical representations of playback zones. The “group” icon providedwithin a graphical representation of a particular zone may be selectableto bring up options to select one or more other zones in the mediaplayback system to be grouped with the particular zone. Once grouped,playback devices in the zones that have been grouped with the particularzone will be configured to play audio content in synchrony with theplayback device(s) in the particular zone. Analogously, a “group” iconmay be provided within a graphical representation of a zone group. Inthis case, the “group” icon may be selectable to bring up options todeselect one or more zones in the zone group to be removed from the zonegroup. Other interactions and implementations for grouping andungrouping zones via a user interface such as the user interface 400 arealso possible. The representations of playback zones in the playbackzone region 420 may be dynamically updated as playback zone or zonegroup configurations are modified.

The playback status region 430 may include graphical representations ofaudio content that is presently being played, previously played, orscheduled to play next in the selected playback zone or zone group. Theselected playback zone or zone group may be visually distinguished onthe user interface, such as within the playback zone region 420 and/orthe playback status region 430. The graphical representations mayinclude track title, artist name, album name, album year, track length,and other relevant information that may be useful for the user to knowwhen controlling the media playback system via the user interface 400.

The playback queue region 440 may include graphical representations ofaudio content in a playback queue associated with the selected playbackzone or zone group. In some embodiments, each playback zone or zonegroup may be associated with a playback queue containing informationcorresponding to zero or more audio items for playback by the playbackzone or zone group. For instance, each audio item in the playback queuemay comprise a uniform resource identifier (URI), a uniform resourcelocator (URL) or some other identifier that may be used by a playbackdevice in the playback zone or zone group to find and/or retrieve theaudio item from a local audio content source or a networked audiocontent source, possibly for playback by the playback device.

In one example, a playlist may be added to a playback queue, in whichcase information corresponding to each audio item in the playlist may beadded to the playback queue. In another example, audio items in aplayback queue may be saved as a playlist. In a further example, aplayback queue may be empty, or populated but “not in use” when theplayback zone or zone group is playing continuously streaming audiocontent, such as Internet radio that may continue to play untilotherwise stopped, rather than discrete audio items that have playbackdurations. In an alternative embodiment, a playback queue can includeInternet radio and/or other streaming audio content items and be “inuse” when the playback zone or zone group is playing those items. Otherexamples are also possible.

When playback zones or zone groups are “grouped” or “ungrouped,”playback queues associated with the affected playback zones or zonegroups may be cleared or re-associated. For example, if a first playbackzone including a first playback queue is grouped with a second playbackzone including a second playback queue, the established zone group mayhave an associated playback queue that is initially empty, that containsaudio items from the first playback queue (such as if the secondplayback zone was added to the first playback zone), that contains audioitems from the second playback queue (such as if the first playback zonewas added to the second playback zone), or a combination of audio itemsfrom both the first and second playback queues. Subsequently, if theestablished zone group is ungrouped, the resulting first playback zonemay be re-associated with the previous first playback queue, or beassociated with a new playback queue that is empty or contains audioitems from the playback queue associated with the established zone groupbefore the established zone group was ungrouped. Similarly, theresulting second playback zone may be re-associated with the previoussecond playback queue, or be associated with a new playback queue thatis empty, or contains audio items from the playback queue associatedwith the established zone group before the established zone group wasungrouped. Other examples are also possible.

Referring back to the user interface 400 of FIG. 4 , the graphicalrepresentations of audio content in the playback queue region 440 mayinclude track titles, artist names, track lengths, and other relevantinformation associated with the audio content in the playback queue. Inone example, graphical representations of audio content may beselectable to bring up additional selectable icons to manage and/ormanipulate the playback queue and/or audio content represented in theplayback queue. For instance, a represented audio content may be removedfrom the playback queue, moved to a different position within theplayback queue, or selected to be played immediately, or after anycurrently playing audio content, among other possibilities. A playbackqueue associated with a playback zone or zone group may be stored in amemory on one or more playback devices in the playback zone or zonegroup, on a playback device that is not in the playback zone or zonegroup, and/or some other designated device. Playback of such a playbackqueue may involve one or more playback devices playing back media itemsof the queue, perhaps in sequential or random order.

The audio content sources region 450 may include graphicalrepresentations of selectable audio content sources from which audiocontent may be retrieved and played by the selected playback zone orzone group. Discussions pertaining to audio content sources may be foundin the following section.

d. Example Audio Content Sources

As indicated previously, one or more playback devices in a zone or zonegroup may be configured to retrieve for playback audio content (e.g.,according to a corresponding URI or URL for the audio content) from avariety of available audio content sources. In one example, audiocontent may be retrieved by a playback device directly from acorresponding audio content source (e.g., a line-in connection). Inanother example, audio content may be provided to a playback device overa network via one or more other playback devices or network devices.

Example audio content sources may include a memory of one or moreplayback devices in a media playback system such as the media playbacksystem 100 of FIG. 1 , local music libraries on one or more networkdevices (such as a control device, a network-enabled personal computer,or a networked-attached storage (NAS), for example), streaming audioservices providing audio content via the Internet (e.g., the cloud), oraudio sources connected to the media playback system via a line-in inputconnection on a playback device or network devise, among otherpossibilities.

In some embodiments, audio content sources may be regularly added orremoved from a media playback system such as the media playback system100 of FIG. 1 . In one example, an indexing of audio items may beperformed whenever one or more audio content sources are added, removedor updated. Indexing of audio items may involve scanning foridentifiable audio items in all folders/directory shared over a networkaccessible by playback devices in the media playback system, andgenerating or updating an audio content database containing metadata(e.g., title, artist, album, track length, among others) and otherassociated information, such as a URI or URL for each identifiable audioitem found. Other examples for managing and maintaining audio contentsources may also be possible.

e. Example Plurality of Networked Devices

FIG. 5 shows an example plurality of devices 500 that may be configuredto provide an audio playback experience based on voice control. Onehaving ordinary skill in the art will appreciate that the devices shownin FIG. 5 are for illustrative purposes only, and variations includingdifferent and/or additional devices may be possible. As shown, theplurality of devices 500 includes computing devices 504, 506, and 508;network microphone devices (NMDs) 512, 514, and 516; playback devices(PBDs) 532, 534, 536, and 538; and a controller device (CR) 522.

Each of the plurality of devices 500 may be network-capable devices thatcan establish communication with one or more other devices in theplurality of devices according to one or more network protocols, such asNFC, Bluetooth, Ethernet, and IEEE 802.11, among other examples, overone or more types of networks, such as wide area networks (WAN), localarea networks (LAN), and personal area networks (PAN), among otherpossibilities.

As shown, the computing devices 504, 506, and 508 may be part of a cloudnetwork 502. The cloud network 502 may include additional computingdevices. In one example, the computing devices 504, 506, and 508 may bedifferent servers. In another example, two or more of the computingdevices 504, 506, and 508 may be modules of a single server.Analogously, each of the computing device 504, 506, and 508 may includeone or more modules or servers. For ease of illustration purposesherein, each of the computing devices 504, 506, and 508 may beconfigured to perform particular functions within the cloud network 502.For instance, computing device 508 may be a source of audio content fora streaming music service.

As shown, the computing device 504 may be configured to interface withNMDs 512, 514, and 516 via communication path 542. NMDs 512, 514, and516 may be components of one or more “Smart Home” systems. In one case,NMDs 512, 514, and 516 may be physically distributed throughout ahousehold, similar to the distribution of devices shown in FIG. 1 . Inanother case, two or more of the NMDs 512, 514, and 516 may bephysically positioned within relative close proximity of one another.Communication path 542 may comprise one or more types of networks, suchas a WAN including the Internet, LAN, and/or PAN, among otherpossibilities.

In one example, one or more of the NMDs 512, 514, and 516 may be devicesconfigured primarily for audio detection. In another example, one ormore of the NMDs 512, 514, and 516 may be components of devices havingvarious primary utilities. For instance, as discussed above inconnection to FIGS. 2 and 3 , one or more of NMDs 512, 514, and 516 maybe the microphone(s) 220 of playback device 200 or the microphone(s) 310of network device 300. Further, in some cases, one or more of NMDs 512,514, and 516 may be the playback device 200 or network device 300. In anexample, one or more of NMDs 512, 514, and/or 516 may include multiplemicrophones arranged in a microphone array.

As shown, the computing device 506 may be configured to interface withCR 522 and PBDs 532, 534, 536, and 538 via communication path 544. Inone example, CR 522 may be a network device such as the network device200 of FIG. 2 . Accordingly, CR 522 may be configured to provide thecontroller interface 400 of FIG. 4 . Similarly, PBDs 532, 534, 536, and538 may be playback devices such as the playback device 300 of FIG. 3 .As such, PBDs 532, 534, 536, and 538 may be physically distributedthroughout a household as shown in FIG. 1 . For illustration purposes,PBDs 536 and 538 may be part of a bonded zone 530, while PBDs 532 and534 may be part of their own respective zones. As described above, thePBDs 532, 534, 536, and 538 may be dynamically bonded, grouped,unbonded, and ungrouped. Communication path 544 may comprise one or moretypes of networks, such as a WAN including the Internet, LAN, and/orPAN, among other possibilities.

In one example, as with NMDs 512, 514, and 516, CR 522 and PBDs 532,534, 536, and 538 may also be components of one or more “Smart Home”systems. In one case, PBDs 532, 534, 536, and 538 may be distributedthroughout the same household as the NMDs 512, 514, and 516. Further, assuggested above, one or more of PBDs 532, 534, 536, and 538 may be oneor more of NMDs 512, 514, and 516.

The NMDs 512, 514, and 516 may be part of a local area network, and thecommunication path 542 may include an access point that links the localarea network of the NMDs 512, 514, and 516 to the computing device 504over a WAN (communication path not shown). Likewise, each of the NMDs512, 514, and 516 may communicate with each other via such an accesspoint.

Similarly, CR 522 and PBDs 532, 534, 536, and 538 may be part of a localarea network and/or a local playback network as discussed in previoussections, and the communication path 544 may include an access pointthat links the local area network and/or local playback network of CR522 and PBDs 532, 534, 536, and 538 to the computing device 506 over aWAN. As such, each of the CR 522 and PBDs 532, 534, 536, and 538 mayalso communicate with each over such an access point.

In one example, a single access point may include communication paths542 and 544. In an example, each of the NMDs 512, 514, and 516, CR 522,and PBDs 532, 534, 536, and 538 may access the cloud network 502 via thesame access point for a household.

As shown in FIG. 5 , each of the NMDs 512, 514, and 516, CR 522, andPBDs 532, 534, 536, and 538 may also directly communicate with one ormore of the other devices via communication means 546. Communicationmeans 546 as described herein may involve one or more forms ofcommunication between the devices, according to one or more networkprotocols, over one or more types of networks, and/or may involvecommunication via one or more other network devices. For instance,communication means 546 may include one or more of for example,Bluetooth™ (IEEE 802.15), NFC, Wireless direct, and/or Proprietarywireless, among other possibilities.

In one example, CR 522 may communicate with NMD 512 over Bluetooth™, andcommunicate with PBD 534 over another local area network. In anotherexample, NMD 514 may communicate with CR 522 over another local areanetwork, and communicate with PBD 536 over Bluetooth. In a furtherexample, each of the PBDs 532, 534, 536, and 538 may communicate witheach other according to a spanning tree protocol over a local playbacknetwork, while each communicating with CR 522 over a local area network,different from the local playback network. Other examples are alsopossible.

In some cases, communication means between the NMDs 512, 514, and 516,CR 522, and PBDs 532, 534, 536, and 538 may change depending on types ofcommunication between the devices, network conditions, and/or latencydemands. For instance, communication means 546 may be used when NMD 516is first introduced to the household with the PBDs 532, 534, 536, and538. In one case, the NMD 516 may transmit identification informationcorresponding to the NMD 516 to PBD 538 via NFC, and PBD 538 may inresponse, transmit local area network information to NMD 516 via NFC (orsome other form of communication). However, once NMD 516 has beenconfigured within the household, communication means between NMD 516 andPBD 538 may change. For instance, NMD 516 may subsequently communicatewith PBD 538 via communication path 542, the cloud network 502, andcommunication path 544. In another example, the NMDs and PBDs may nevercommunicate via local communications means 546. In a further example,the NMDs and PBDs may communicate primarily via local communicationsmeans 546. Other examples are also possible.

In an illustrative example, NMDs 512, 514, and 516 may be configured toreceive voice inputs to control PBDs 532, 534, 536, and 538. Theavailable control commands may include any media playback systemcontrols previously discussed, such as playback volume control, playbacktransport controls, music source selection, and grouping, among otherpossibilities. In one instance, NMD 512 may receive a voice input tocontrol one or more of the PBDs 532, 534, 536, and 538. In response toreceiving the voice input, NMD 512 may transmit via communication path542, the voice input to computing device 504 for processing. In oneexample, the computing device 504 may convert the voice input to anequivalent text command, and parse the text command to identify acommand. Computing device 504 may then subsequently transmit the textcommand to the computing device 506. In another example, the computingdevice 504 may convert the voice input to an equivalent text command,and then subsequently transmit the text command to the computing device506. The computing device 506 may then parse the text command toidentify one or more playback commands.

For instance, if the text command is “Play ‘Track 1’ by ‘Artist 1’ from‘Streaming Service 1’ in ‘Zone 1’,” The computing device 506 mayidentify (i) a URL for “Track 1” by “Artist 1” available from “StreamingService 1,” and (ii) at least one playback device in “Zone 1.” In thisexample, the URL for “Track 1” by “Artist 1” from “Streaming Service 1”may be a URL pointing to computing device 508, and “Zone 1” may be thebonded zone 530. As such, upon identifying the URL and one or both ofPBDs 536 and 538, the computing device 506 may transmit viacommunication path 544 to one or both of PBDs 536 and 538, theidentified URL for playback. One or both of PBDs 536 and 538 mayresponsively retrieve audio content from the computing device 508according to the received URL, and begin playing “Track 1” by “Artist 1”from “Streaming Service 1.”

One having ordinary skill in the art will appreciate that the above isjust one illustrative example, and that other implementations are alsopossible. In one case, operations performed by one or more of theplurality of devices 500, as described above, may be performed by one ormore other devices in the plurality of device 500. For instance, theconversion from voice input to the text command may be alternatively,partially, or wholly performed by another device or devices, such as NMD512, computing device 506, PBD 536, and/or PBD 538. Analogously, theidentification of the URL may be alternatively, partially, or whollyperformed by another device or devices, such as NMD 512, computingdevice 504, PBD 536, and/or PBD 538.

f. Example Network Microphone Device

FIG. 6 shows a functional block diagram of an example network microphonedevice 600 that may be configured to be one or more of NMDs 512, 514,and 516 of FIG. 5 . As shown, the network microphone device 600 includesa processor 602, memory 604, a microphone array 606, a network interface608, a user interface 610, software components 612, and speaker(s) 614.One having ordinary skill in the art will appreciate that other networkmicrophone device configurations and arrangements are also possible. Forinstance, network microphone devices may alternatively exclude thespeaker(s) 614 or have a single microphone instead of microphone array606.

The processor 602 may include one or more processors and/or controllers,which may take the form of a general or special-purpose processor orcontroller. For instance, the processing unit 602 may includemicroprocessors, microcontrollers, application-specific integratedcircuits, digital signal processors, and the like. The memory 604 may bedata storage that can be loaded with one or more of the softwarecomponents executable by the processor 602 to perform those functions.Accordingly, memory 604 may comprise one or more non-transitorycomputer-readable storage mediums, examples of which may includevolatile storage mediums such as random access memory, registers, cache,etc. and non-volatile storage mediums such as read-only memory, ahard-disk drive, a solid-state drive, flash memory, and/or anoptical-storage device, among other possibilities.

The microphone array 606 may be a plurality of microphones arranged todetect sound in the environment of the network microphone device 600.Microphone array 606 may include any type of microphone now known orlater developed such as a condenser microphone, electret condensermicrophone, or a dynamic microphone, among other possibilities. In oneexample, the microphone array may be arranged to detect audio from oneor more directions relative to the network microphone device. Themicrophone array 606 may be sensitive to a portion of a frequency range.In one example, a first subset of the microphone array 606 may besensitive to a first frequency range, while a second subset of themicrophone array may be sensitive to a second frequency range. Themicrophone array 606 may further be arranged to capture locationinformation of an audio source (e.g., voice, audible sound) and/or toassist in filtering background noise. Notably, in some embodiments themicrophone array may consist of only a single microphone, rather than aplurality of microphones.

The network interface 608 may be configured to facilitate wirelessand/or wired communication between various network devices, such as, inreference to FIG. 5 , CR 522, PBDs 532-538, computing device 504-508 incloud network 502, and other network microphone devices, among otherpossibilities. As such, network interface 608 may take any suitable formfor carrying out these functions, examples of which may include anEthernet interface, a serial bus interface (e.g., FireWire, USB 2.0,etc.), a chipset and antenna adapted to facilitate wirelesscommunication, and/or any other interface that provides for wired and/orwireless communication. In one example, the network interface 608 may bebased on an industry standard (e.g., infrared, radio, wired standardsincluding IEEE 802.3, wireless standards including IEEE 802.11a,802.11b, 802.11g, 802.11n, 802.11ac, 802.15, 4G mobile communicationstandard, and so on).

The user interface 610 of the network microphone device 600 may beconfigured to facilitate user interactions with the network microphonedevice. In one example, the user interface 608 may include one or moreof physical buttons, graphical interfaces provided on touch sensitivescreen(s) and/or surface(s), among other possibilities, for a user todirectly provide input to the network microphone device 600. The userinterface 610 may further include one or more of lights and thespeaker(s) 614 to provide visual and/or audio feedback to a user. In oneexample, the network microphone device 600 may further be configured toplayback audio content via the speaker(s) 614.

Moving now to several example implementations, implementations 700, 900and 1100 shown in FIGS. 7, 9, and 11 , respectively present exampleembodiments of techniques described herein. These example embodimentsthat can be implemented within an operating environment including, forexample, the media playback system 100 of FIG. 1 , one or more of theplayback device 200 of FIG. 2 , or one or more of the control device 300of FIG. 3 , as well as other devices described herein and/or othersuitable devices. Further, operations illustrated by way of example asbeing performed by a media playback system can be performed by anysuitable device, such as a playback device or a control device of amedia playback system. Implementations 700, 900, and 1100 may includeone or more operations, functions, or actions as illustrated by one ormore of blocks shown in FIGS. 7, 9, and 11 . Although the blocks areillustrated in sequential order, these blocks may also be performed inparallel, and/or in a different order than those described herein. Also,the various blocks may be combined into fewer blocks, divided intoadditional blocks, and/or removed based upon the desired implementation.

In addition, for the implementations disclosed herein, the flowchartsshow functionality and operation of one possible implementation ofpresent embodiments. In this regard, each block may represent a module,a segment, or a portion of program code, which includes one or moreinstructions executable by a processor for implementing specific logicalfunctions or steps in the process. The program code may be stored on anytype of computer readable medium, for example, such as a storage deviceincluding a disk or hard drive. The computer readable medium may includenon-transitory computer readable medium, for example, such ascomputer-readable media that stores data for short periods of time likeregister memory, processor cache, and Random Access Memory (RAM). Thecomputer readable medium may also include non-transitory media, such assecondary or persistent long term storage, like read only memory (ROM),optical or magnetic disks, compact-disc read only memory (CD-ROM), forexample. The computer readable media may also be any other volatile ornon-volatile storage systems. The computer readable medium may beconsidered a computer readable storage medium, for example, or atangible storage device. In addition, for the implementations disclosedherein, each block may represent circuitry that is wired to perform thespecific logical functions in the process.

III. Example Techniques To Duck Audio

As discussed above, embodiments described herein may facilitate speechcomprehension in the presence of noise, such as music playback. FIG. 7illustrates an example implementation 700 by which a playback deviceducks audio being played back. Such ducking may improve speechcomprehension in the presence of the played back audio.

a. Detect that an Event is Anticipated in a Given Environment

At block 702, implementation 700 involves detecting that an event isanticipated in a given environment. For instance, a playback device,such as playback device 114 of media playback system 100, may detectthat an event is anticipated in a given environment (e.g., within theexample home environment or a subset of its rooms and spaces, such as inthe Kitchen). Such an anticipated event may be an event that is expectedor predicted to occur but has not yet taken place (or perhaps has notfully taken place). During the event (or a portion thereof), audio thatis being played by one or more playback devices of a media playbacksystem (e.g., any of playback devices 102-124 of media playback system100) may be ducked. Ducking is an audio effect by which the level of oneaudio signal is reduced during the presence of another audio signal.

As noted above, audio that is being played back may be ducked.Implementation 700 may involve detecting that an event is anticipatedwhile playing back first audio in the given environment. The first audiomight be music, talk radio or other programming, television or hometheater content, audio from an analog or digital line-in to the playbackdevice, as well as other types of audio or a combination of multipletypes of audio. Ultimately, the playback device may duck the first audioduring the event (or during a portion of the event).

Some example events may involve playback of second audio. Detecting thatsuch an event is anticipated may involve detecting that playback of thesecond audio is anticipated. A playback device may anticipate playbackof second audio when the playback device receives an instruction toplayback the second audio via a network interface (and/or receives thesecond audio itself for playback, perhaps as an audio stream).Alternatively, a first playback device (e.g., playback device 112) maydetect that playback of the second audio by one or more second playbackdevices is anticipated, perhaps by receiving a transmission indicatingthat the one or more second playback devices (e.g., one or more of theplayback devices of media playback system 100) are expected to play backsecond audio.

In some cases, the second audio may be related to a voice service. Somevoice services include artificial intelligence to process voice inputsand generate responses to those voice inputs. For instance, the secondaudio may include a spoken voice input to a voice service (e.g., “HeyKitchen, what is the weather today?”). The second audio may additionallyor alternatively include a spoken response to a voice input (e.g., “Theweather is clear and sunny with a high of 75 degrees and a low of 68degrees”). The playback device may receive such a response via a networkinterface from a voice service or from an NMD, among other sources.

Detecting that an event is anticipated in a given environment mayinvolve receiving an indication that a voice command with the givenenvironment is anticipated. For instance, an NMD (e.g., NMD 132 of FIG.1 ) may detect a voice input and transmit an indication to playbackdevice 114 that second audio is anticipated. Detecting that an event isanticipated in the given environment may involve receiving thatindication.

In some cases, a voice input may include a wake word and a voicecommand. Detection of a spoken wake-word (e.g., “Hey Siri,” “Ok,Google,” “Sonos,” or “Hey, Alexa,” among others) may cause a NMD tostart listening for a voice command. As such, detection of a wake wordmay indicate that a voice command is expected in the given environment.A playback device may detect that an event (e.g., a voice command and/oran audio response to the voice command) is anticipated by receiving anindication from an NMD that a wake word was detected. Alternatively, anNMD may be integrated with a playback device. In such implementations,the playback device may detect that an event is anticipated by detectinga voice input via one or more microphones (e.g., a far-field microphonearray). The voice input or a portion thereof (e.g., a wake-word) maycause the playback device to anticipate the event (e.g., second audioinclude a voice command and/or an audio response to the voice command).

The second audio might include other audio streams as well. Examplestreams include any stream from a cloud services (e.g., a stream from ahome cloud service indicating that a “smart” device (e.g., an applianceor other smart home device with an processor and network interface) isexperiencing a condition. For instance, “smart” thermostat may cause avarious audio streams indicating respective conditions to be played back(e.g., “HVAC system cooling” or “HVAC system fault”).

Other example streams may be sent from other network-connected deviceswithin the environment. For instance, a “smart” doorbell may instructthe playback device to output a doorbell track (e.g., a chime) perhapsby streaming the doorbell track to the playback device. As anotherexample, a “smart” refrigerator may stream a spoken message (e.g., amessage indicating that certain food is past its expiration date).Detecting that an event is anticipated may involve receiving aninstruction to play back such a stream, receiving the stream itself, orreceiving an indication that another playback device is instructed toplay back the stream, among other examples.

In some examples, detecting that an event is anticipated may involvedetecting input data from one or more control interfaces (e.g.,controller interface 400 displayed on a control device or a physicalbutton on a playback device, among other options). The input data mayindicate an instruction that causes the playback device to play backsecond audio. As noted above, the second audio may include a spokenresponse from a voice service, an audio stream from a “smart” device, oran audio stream from a cloud service, among other examples. Forinstance, a remote control may include a microphone button that causesthe remote control to start listening for a voice input via one or moremicrophones. Detecting a press of such a button may cause the playbackdevice to anticipate an event that involves second audio within theenvironment (e.g., a voice input and/or an audio response to that voiceinput).

As noted above, a playback device may detect that the event isanticipated while playing back first audio in the given environment. Forinstance, playback device 114 of media playback system 100 in FIG. 1 maystream first audio and play the streamed audio in the Kitchen. In somecases, the playback device may be part of a grouping of playbackdevices, such as a bonded zone or zone group. In such cases, playingback first audio in the given environment may involve playing audio insynchrony with other playback devices in the grouping. For instance,playback devices 104, 106, 108, and 110 may play back respectivechannels of first audio that includes surround sound (e.g., hometheater) audio. As another example, playback devices 104, 106, 108, 110,112 and 114 may be joined into a zone group to play music in synchrony.Many examples are possible.

b. Determine Loudness of Background Noise in Given Environment

Referring back to FIG. 7 , at block 704, implementation 700 involvesdetermining a loudness of background noise in the given environment. Forinstance, the playback device may measure background noise in the givenenvironment using one or more microphones. Alternatively, the playbackdevice may transmit a request that causes one or more NMDs to measurebackground noise in the given environment. The background noise mayinclude ambient noise within the given environment (e.g., conversationsbetween people, appliances, HVAC, outdoor noise such as traffic, amongother possible sources). The playback device may determine loudnesswhile playing back the first audio in the given environment.

In some cases, multiple NMDs may perform the measurement of backgroundnoise. For instance, the playback device may transmit to multiple NMDsrespective requests to measure background noise. Alternatively, one ormore first NMDs may receive an instruction to measure background noiseand cause one or more second NMDs to measure background noise. The NMDsmay measure the background noise using one or more microphones (e.g.,using a far-field microphone array). For instance, NMD 132 and controldevices 126 shown in Figure (which may have an integrated NMD) may eachperform a measurement of background noise within the Living Room/DiningRoom/Kitchen environment.

A suitable processing device, such as the playback device or an NMD, maycombine multiple measurements of background noise to yield arepresentation of loudness of background noise in the given environment.In some cases, the processing device may average multiple measurementsof background noise to determine the loudness. In some cases,measurements from respective NMDs may be weighted (e.g., prioritized)differently, perhaps based on the quality of measurement. Quality ofmeasurement may vary based on an NMD's position within the givenenvironment (which may influence how well the NMD is able to measurebackground noise), the quality of microphone(s) used to measurebackground noise, or other factors that might influence measurementquality.

In some implementations, the processing device may offset the firstaudio that the playback device is playing back within the measurement ofbackground noise in the given environment. By offsetting the first audiofrom the measurement, the measurement may more accurately represent theambient noise other than the first audio that is present within theenvironment.

Various techniques may be used to offset the first audio from themeasurement. For instance, the measurement may use acoustic echocancellation or beam-forming to offset the first audio from themeasurement, among other suitable recording techniques. Alternatively,the acoustic response of the playback device and the first audio mayeach be known, such that the response produced by the playback device inplaying back the first audio is known (to at least some approximatedegree). With this response known, the processing device can offset thefirst audio from a measurement of background noise by subtraction. Othertechniques are possible as well.

In some cases, the measurement device(s) and/or the processing device(s)may transmit measurement(s) of background noise to the playback device.This measurement may be represented as a decibel value of a known scaleor an identifier of a range (e.g., a loudness-window) in which theloudness measurement falls, among any suitable indication of themeasured loudness. In some cases, the transmission may represent anerror state indicating that a loudness measurement could not beobtained.

As indicated above, in some cases, the playback device might not be ableto obtain a loudness measurement. For instance, there might not be anysuitable NMDs within the given environment to perform the measurement.Or, as another example, there may be a connection issue between NMDswithin the given environment and the playback device. Other issues arepossible as well.

When the playback device is unable to obtain a measurement of thebackground noise, the playback device may estimate the background noise.For instance, the playback device may estimate the background noise assome default background noise level. Alternatively, the playback devicemay estimate the background noise as the last known background noiselevel within the environment.

As yet another example, the playback device may estimate the backgroundnoise based on a measurement of background noise in another room. Forexample, playback device 114 may estimate background noise in the LivingRoom/Dining Room/Kitchen environment using a measurement of backgroundnoise in the Bedroom environment from control device 128. The estimateof background noise in the Living Room/Dining Room/Kitchen environmentbased the measurement of background noise in the Bedroom environment maybe adjusted based on the relative locations of two environments and anyobstructions between the two environments, which may be known. Emittingsound in one environment and recording that sound in another mayfacilitate mapping transforms between environments (e.g., between roomsor spaces).

c. Duck the First Audio

In FIG. 7 , at block 706, implementation 700 involves ducking the firstaudio. For instance, the playback device may duck the first audio thatis being played back by the playback device. As noted above, ducking isan audio effect by which the level of one audio signal is reduced duringthe presence of another audio signal. As used herein, ducking may referto volume reduction of the first audio that the playback device isplaying back during the anticipated event. For example, the playbackdevice may reduce the volume of the first audio while the second audiois present (e.g., playing back or being spoken).

As noted above, in some instances, the anticipated event may involvesecond audio. The second audio may include a voice input and/or a spokenresponse from a voice service to a voice input. In some examples, theplayback device ducks the first audio (e.g., one or more audio tracks,such as music) during the voice input and/or during the spoken responsefrom the voice service. Such ducking may assist an NMD in comprehendingthe voice input and/or a user in comprehending a spoken response.

The amount of ducking (i.e., the amount of volume reduction of the firstaudio) may vary based on desired outcomes of the ducking. For instance,the loudness of the first audio may be reduced to the volume level ofthe second audio such that the first audio and the second audio areoutput at approximately equal loudness levels. Other examples arepossible.

In some examples, the first audio may be ducked by a specific amountbased on the difference between loudness of the first audio and thebackground noise. For instance, where the playback device is playingback the first audio at a given loudness, the playback device may duckthe first audio in proportion to the difference between the givenloudness and the determined loudness of the background noise. Duckingthe first audio by such an amount may assist in keeping the ducked firstaudio above the noise floor.

To illustrate, in one example a party might be held in the LivingRoom/Dining Room/Kitchen area shown in FIG. 1 . During the party,playback devices 104, 106, 108, 110, 112, and/or 114 may play back firstaudio (e.g., music) at a given volume level. Music played at that volumelevel may generate a dynamic range centered around a given loudness. Thedynamic range of the first audio is the difference between the quiet andloudest parts of the first audio. Talking, dancing, and/or other actionsby guests at the party may generate a relatively high level ofbackground noise. Given this relatively loud background noise, if thefirst audio is set at a relatively low volume, some part of the firstaudio (i.e., the quiet parts of music at the low end of the dynamicrange) may be below the noise floor. Alternatively, if the first audiois set at a relatively high volume, more (or all) of the first audio maybe above the noise floor. When the first audio is ducked, the quieterparts of the first audio may go below the noise floor. Ducking the firstaudio in proportion to the difference between the given loudness and thedetermined loudness of the background noise may help to avoid portionsof the first audio being lost under the noise floor.

As noted above, in some examples, the playback device may duck the firstaudio while the second audio is present. FIG. 8 includes a chart 800. Inchart 800, time is plotted along the x-axis and loudness is plottedalong the y-axis. At time t₀, a playback device is playing first audio802 at loudness level l₀. From time t₁ to time t₂, the playback devicereduces the loudness of first audio 802 from loudness level l₀ toloudness level l₁ so as to duck the first audio 802 in the presence ofsecond audio 804.

In some cases, the playback device may duck the first audio itself. Forinstance, the playback device may adjust an amplifier level to reducethe volume of the first audio. Alternatively, the playback device mayapply a filter to reduce the volume of the first audio. As yet anotherexample, another device may process the first audio to reduce the volumeof the first audio. Other examples are possible as well.

d. Play Back the Ducked First Audio Concurrently with the Second Audio

In FIG. 7 , at block 708, implementation 700 involves playing back theducked first audio concurrently with the second audio. For instance, theplayback device may receive a stream of the second audio and play backthat stream of second audio concurrently with the ducked first audio. Asnoted above, a playback device may receive a spoken response to a voiceinput from a voice service or intermediary device. The playback devicemay play back ducked music (e.g., one or more audio tracks) concurrentlywith the spoken response from a voice input. As another example, theplayback device may play back a ducked streaming radio stationconcurrently with an alarm from a “smart” device such as a doorbell orrefrigerator. In a further example, the second audio may be a phone calland the playback device may play back audio from the phone callconcurrently with the ducked first audio. As noted above, many differenttypes of first and second audio are contemplated.

As noted above, a playback device may be part of grouping of playbackdevices, such as a bonded zone or zone group. In such cases, theplayback device may play the first audio in synchrony with otherplayback devices in the grouping. In some implementations, all of theplayback devices in the grouping may play back the ducked first audioconcurrently with the second audio. In other implementations, a subsetof the playback devices in the grouping may play back the ducked firstaudio concurrently with the second audio, while the other playbackdevices continue to play back the first audio without ducking. In yetfurther examples, a subset of the playback devices in the grouping mayplay back the second audio while the other playback devices play backthe first audio. Other examples are possible as well.

The playback device may continue to duck the first audio until theanticipated event has completed or until a future event occurs, amongother examples. For instance, if the event is a voice interaction with avoice service, the playback device may duck the first audio while a useris speaking a voice input and/or while playing back a spoken responsefrom the voice service. As another example, if the event is a phonecall, the playback device may duck the first audio until the phone callends (e.g., until the parties hang up). Generally, in examples where thesecond audio is an audio stream, the playback device may duck the firstaudio until the second audio completes play back.

To illustrate, referring back to FIG. 8 , the second audio 804 is outputfrom time t₂ to t₃. The first audio 802 is ducked from time t₂ until t₃.Time t₃ may correspond to the end of the anticipated event beginning att₂ or to a future event detected by the playback device. From time t₃ tot₄, the ducking is reversed by raising the volume level from l₁ to l₂.

IV. Example Techniques to Compress Audio

As discussed above, embodiments described herein may facilitatecompressing audio in the presence of second audio. FIG. 9 illustrates anexample implementation 900 by which a playback device compresses firstaudio. The playback device may compress the first audio while duckingthe first audio, as described above in connection with implementation700.

a. Determine Loudness of First Audio and Background Noise

At block 902, implementation 900 involves determining a loudness offirst audio and background noise in a given environment. For instance, aplayback device may determine the loudness of first audio played back bythe playback device (and possibly one or more additional playbackdevices in synchrony with the playback device). The first audio may beany suitable audio, such as any of the examples of first audio discussedabove in connection with implementation 700, among other examples. Theplayback device may determine a loudness of background noise using anysuitable technique, such as the example techniques described inconnection with block 704 of implementation 700.

In some instances, the first audio may be ducked first audio, such asthe ducked first audio discussed above in connection with implementation700. Ducked first audio may refer to audio that has been temporarilyreduced in volume based on the presence of second audio.

The playback device may determine the loudness of the first audio usingany suitable technique. For instance, the playback device may have aknown volume setting (perhaps reduced by a known amount throughducking). The playback device may have a known equalization.Furthermore, the playback device may have a known response in the givenenvironment, perhaps via a calibration procedure. The first audio mayhave a known or assumed level (e.g., −6 dB from an average master).Given one or more of these known values, the playback device mayestimate the loudness of the first audio.

b. Compare Determined Loudness of First Audio with Loudness ofBackground Noise

In FIG. 9 , at block 904, implementation 900 involves comparing thedetermined loudness of the first audio with the determined loudness ofthe background noise. For instance, a playback device may determine adifference between a loudness of first audio (possibly ducked firstaudio) and a given dynamic range. The playback device may furtherdetermine whether the difference between the loudness of the (ducked)first audio and the given dynamic range is less than or greater than thedetermined loudness of the background noise. The given dynamic range maybe a desired dynamic range of the first audio (e.g., a dynamic range ofmusic playback).

c. Compressing First Audio

In FIG. 9 , at block 906, implementation 900 involves compressing thefirst audio. The playback device may compress the first audio when thedetermined difference between the loudness of the (ducked) first audioand the given dynamic range is less than the determined loudness of thebackground noise. This determination may indicate that a portion of thedynamic range of the first audio is below the noise floor created by thebackground noise. By compressing the first audio in such circumstances,some or all of the dynamic range of the first audio may be raised abovethe noise floor. When the determined difference between the loudness ofthe (ducked) first audio and the given dynamic range is greater than thedetermined loudness of the background noise, the playback might notapply compression since such compression might be unnecessarily reducethe dynamic range of the first audio.

The amount of compression may be a function of the difference betweenthe determined loudness of the background noise and the given dynamicrange. For instance, when the difference is relatively large such thatthe low end of the dynamic range is relatively further below the noisefloor created by the background noise, then the playback device maycompress the first audio more to bring more (or all) of the dynamicrange above the noise floor. Conversely, when the difference isrelatively small such that the low end of the dynamic range is justbelow the noise floor, the playback device might compress the dynamicrange of the first audio relatively less.

To illustrate, FIG. 10 is a diagram illustrating a dynamic range 1000Aof first audio (e.g., music) and a dynamic range 1002A of second audio(e.g., voice). As shown, dynamic range 1000A and dynamic range 1002overlap, which may make the first audio and/or the second audio hard tocomprehend. At time t₁, the first audio is ducked, which causes adynamic range 1000B of the ducked first audio to be below the dynamicrange 1002 of the second audio. However, when ducked, the dynamic rangeof the first audio is below a noise floor 1004. In this case, quietdetails in the first audio may be indiscernible over background noise.At time t₂, the ducked first audio is compressed, which causes a dynamicrange 1000C of the ducked and compressed audio to be above the noisefloor 1004. Although FIG. 10 describes ducking and compression asoccurring in a particular order, these operations may be performedconcurrently or in a different order.

Although examples techniques described in connection with implementation1000 describe compression being applied based on a comparison betweenthe determined loudness of background noise and the first audio,compression may be applied to the first audio under other conditions aswell. For instance, compression may be applied based on content type(e.g., applied to music or talk radio) or background noise level, amongother options. In some cases, compression is always applied to firstaudio when second audio is present.

V. Example Techniques to Apply Equalization

As discussed above, embodiments described herein may improvespeech-to-noise ratio within a given environment. FIG. 11 illustrates anexample implementation 1100 by which a playback device selectivelyapplies an equalization to audio content being played back.

a. Play Audio Content in Given Environment

At block 1102, implementation 1100 involves playing audio content in agiven environment. For instance, one or more playback devices (e.g., anycombination of playback devices 102-124 in FIG. 1 ) may play back audiocontent in one or more rooms of the example home environment in FIG. 1 .In one example, playback devices 112 and 114 may play back music in theKitchen/Dining Room environment. The audio content may be music or anyother suitable audio content.

b. Detect that a Signal-to-Noise Ratio in Given Environment is BelowSpeech Threshold

In FIG. 11 , at block 1104, implementation 1100 involves detecting thata signal-to-noise ratio in the given environment is below a speechthreshold. For instance, a playback device (e.g., playback device 114 ofFIG. 1 ) may determine that a signal-to-noise ratio in a givenenvironment (i.e., the Kitchen or the combined Dining Room/Kitchen area)is below a speech threshold. A signal-to-noise ratio that is below thespeech threshold may indicate that an improvement to signal-to-noiseratio in the given environment would facilitate comprehension of speechin that environment.

In some implementations, detecting that the signal-to-noise ratio in thegiven environment is below the speech threshold may involve detecting anumber of people in the given environment. The playback device mayassume that the signal-to-noise ratio in the given environment is belowthe speech threshold when there are more than a given number of peoplein the room (e.g., two or more). The playback device may detect a numberof people in the environment by detecting signals from their respectivesmartphones or other devices using a network interface (e.g., usingBluetooth® beacons or WiFi® device detection). In another case, theplayback device may detect sound pressure level of background noise inthe given environment, perhaps by querying one or more NMDs for ameasurement. A high sound pressure level of background noise mayindicate that the signal-to-noise ratio in the given environment isbelow the speech threshold. In further implementations, user input mayindicate a number of persons in the environment.

In other cases, the playback device may anticipate that speech will bepresent in the environment. For example, the playback device may receivean indication of a wake-word in the given environment, which may causethe playback device to anticipate a voice command. In other examples,the playback device may receive an audio stream representing speech tobe played back by the playback device. Alternatively, the playbackdevice may receive an indication that another playback device in theenvironment is outputting speech. The speech may be audio of a telephonecall or a spoken response from a voice service, among other examples ofhuman or computer-generated speech. When speech is present in theenvironment, the playback device may assume that the signal-to-noiseratio in the given environment is below the speech threshold.

c. Apply Equalization to Audio Content

In FIG. 11 , at block 1106, implementation 1100 involves applying anequalization to the audio content. For instance, playback device 114 mayfilter the audio content (e.g., using one or more digital or analogfilters) to a particular equalization. The equalization may cut theaudio content at frequencies in the audio content corresponding to humanspeech (e.g., 150 Hz-3 kHz). Such filtering may include filtering at thefundamental frequencies of human speech (e.g., 100 Hz for males and 180Hz for females). In some cases, the filtering may cut the audio contentmore at the fundamental frequencies of human speech. Filtering the audiocontent to reduce volume in frequencies corresponding to human speechmay improve the speech-to-noise ratio in the given environment.

Filtering of frequencies in the audio content corresponding to humanspeech may reduce overall perceived loudness of the audio content. Insome cases, the playback devices may offset this decrease in overallloudness by boosting frequencies above and/or below the frequencies inthe audio content corresponding to human speech (e.g., bass and treblefrequencies). In some cases, the playback device may use an equalloudness matching algorithm to boost frequencies by specific amounts tooffset cutting of the frequencies in the audio content corresponding tohuman speech. Alternatively, overall gain of the audio content may beincreased to offset the filtering of frequencies in the audio contentcorresponding to human speech.

The playback device may continue to filter the audio content while thesignal-to-noise ratio in the given environment is below the speechthreshold, among other examples. For instance, if the event is a voiceinteraction with a voice service, the playback device may filter theaudio content while a user is speaking a voice input and/or whileplaying back a spoken response from the voice service. As anotherexample, if the event is a phone call, the playback device may filterthe audio content until the phone call ends (e.g., until the partieshang up). Other examples are possible as well.

VI. Conclusion

The description above discloses, among other things, various examplesystems, methods, apparatus, and articles of manufacture including,among other components, firmware and/or software executed on hardware.It is understood that such examples are merely illustrative and shouldnot be considered as limiting. For example, it is contemplated that anyor all of the firmware, hardware, and/or software aspects or componentscan be embodied exclusively in hardware, exclusively in software,exclusively in firmware, or in any combination of hardware, software,and/or firmware. Accordingly, the examples provided are not the onlyway(s) to implement such systems, methods, apparatus, and/or articles ofmanufacture.

(Feature 1) A method comprising while playing back first audio in agiven environment at a given loudness: (a) detecting that an event isanticipated in the given environment, wherein the event involvesplayback of second audio and (b) determining a loudness of backgroundnoise in the given environment, wherein the background noise comprisesambient noise in the given environment; ducking the first audio inproportion to a difference between the given loudness of the first audioand the determined loudness of the background noise; and playing backthe ducked first audio concurrently with the second audio.

(Feature 2) The method of feature 1, wherein playing back the duckedfirst audio concurrently with the second audio comprises determiningthat a difference between a loudness of the ducked first audio and agiven dynamic range is (a) less than the determined loudness of thebackground noise or (b) greater than the determined loudness of thebackground noise; when the determined difference between the loudness ofthe ducked first audio and the given dynamic range is less than thedetermined loudness of the background noise, compressing the first audioto a dynamic range that is louder than the determined loudness of thebackground noise and playing back the compressed first audio; and whenthe determined difference between the loudness of the ducked first audioand the given dynamic range is greater than the determined loudness ofthe background noise, playing back the first audio without compression.

(Feature 3) The method of feature 1, wherein detecting that the event isanticipated in the given environment comprises receiving an indicationthat a voice command within the given environment is anticipated.

(Feature 4) The method of feature 3, wherein receiving the indicationthat the voice command within the given environment is anticipatedcomprises detecting, via one or more microphones, a voice inputcomprising a wake-word.

(Feature 5) The method of feature 3, wherein the first audio comprisesone or more audio tracks, wherein the second audio comprises a spokenresponse to the voice command received from a voice service, and whereinplaying back the ducked first audio concurrently with the second audiocomprises playing back the one or more audio tracks concurrently withthe spoken response to the voice command.

(Feature 6) The method of feature 3, wherein playing back the duckedfirst audio concurrently with the second audio comprises detecting thata signal-to-noise ratio within the given environment is below a voiceinput threshold; and responsively, filtering the first audio, whereinfiltering the first audio comprises cutting the first audio in afrequency range corresponding to human speech.

(Feature 7) The method of feature 1, wherein filtering the first audiofurther comprises boosting the first audio outside the frequency rangecorresponding to human speech.

(Feature 8) The method of feature 1, wherein the playback device is afirst playback device of a group of playback device that includes one ormore second playback devices, and wherein playing back the ducked firstaudio concurrently with the second audio comprises playing back theducked first audio concurrently with the second audio in synchrony withthe one or more second playback devices.

(Feature 9) The method of feature 1, wherein determining the loudness ofbackground noise in the given environment comprises measuring theloudness of the background noise in the given environment via one ormore microphone.

(Feature 10) The method of feature 9, wherein at least one of the one ormore microphones is housed in a networked microphone device that isdistinct from the playback device, and wherein measuring the loudness ofthe background noise in the given environment via one or moremicrophones comprises causing the networked microphone device to measurethe loudness of the background noise in the given environment.

(Feature 11) The method of feature 9, wherein measuring the loudness ofthe background noise in the given environment comprises offsetting thefirst audio being played back by the playback device from themeasurement of the background noise in the given environment.

(Feature 12) The method of feature 1, wherein the operations furthercomprise detecting that the event has completed, and wherein ducking thefirst audio comprises ducking the first audio until the event hascompleted.

(Feature 13) A tangible, non-transitory computer-readable medium havingstored therein instructions executable by one or more processors tocause a device to perform the method of any of features 1-12.

(Feature 14) A playback device configured to perform the method of anyof features 1-12.

(Feature 15) A media playback system configured to perform the method ofany of features 1-12.

The specification is presented largely in terms of illustrativeenvironments, systems, procedures, steps, logic blocks, processing, andother symbolic representations that directly or indirectly resemble theoperations of data processing devices coupled to networks. These processdescriptions and representations are typically used by those skilled inthe art to most effectively convey the substance of their work to othersskilled in the art. Numerous specific details are set forth to provide athorough understanding of the present disclosure. However, it isunderstood to those skilled in the art that certain embodiments of thepresent disclosure can be practiced without certain, specific details.In other instances, well known methods, procedures, components, andcircuitry have not been described in detail to avoid unnecessarilyobscuring aspects of the embodiments. Accordingly, the scope of thepresent disclosure is defined by the appended claims rather than theforgoing description of embodiments.

When any of the appended claims are read to cover a purely softwareand/or firmware implementation, at least one of the elements in at leastone example is hereby expressly defined to include a tangible,non-transitory medium such as a memory, DVD, CD, Blu-ray, and so on,storing the software and/or firmware.

1. A playback device comprising: a network interface; one or moremicrophones; an audio stage comprising an amplifier; one or morespeakers; one or more processors; a housing, the housing carrying atleast the network interface, the one or more microphones, the audiostage, the one or more speakers, the one or more processors, and datastorage having stored therein instructions executable by the one or moreprocessors to cause the playback device to perform functions comprising:while playing back first audio in a given environment at a givenloudness via the audio stage and the one or more speakers: (a)recording, via the one or more microphones, audio into a buffer; (b)detecting, within the recorded audio, a wake word to invoke a voiceassistant; (c) in response to detecting the wake word: (i) ducking thefirst audio while recording, into the buffer, audio representing a voiceinput to the voice assistant and (ii) sending, to the voice assistant,the recorded audio in the buffer representing the voice input to thevoice assistant; (d) receiving, from the voice assistant in response tothe voice input, second audio representing a spoken response to thevoice input; and in response to receiving the second audio representingthe spoken response to the voice input, ducking the first audio whileplaying back the ducked first audio concurrently with the second audiorepresenting the spoken response to the voice input via the audio stageand the one or more speakers.
 2. The playback device of claim 1, whereinducking the first audio while recording audio representing the voiceinput to the voice assistant comprises ducking the first audio to afirst volume level, and wherein ducking the first audio while playingback the ducked first audio concurrently with the second audiorepresenting the spoken response to the voice input comprises duckingthe first audio to a second volume level that is different from thefirst volume level.
 3. The playback device of claim 2, wherein thefunctions further comprise determining a loudness of background noise inthe given environment, and wherein ducking the first audio to the secondvolume level that is different from the first volume level comprisesducking the first audio to a particular volume level that is based onthe loudness of background noise in the given environment.
 4. Theplayback device of claim 3, wherein ducking the first audio to theparticular volume level that is based on the loudness of backgroundnoise in the given environment comprises ducking the first audio inproportion to a difference between the given loudness of the first audioand the determined loudness of the background noise.
 5. The playbackdevice of claim 3, wherein playing back the ducked first audioconcurrently with the second audio comprises: determining that adifference between a loudness of the ducked first audio and a givendynamic range is (a) less than the determined loudness of the backgroundnoise or (b) greater than the determined loudness of the backgroundnoise; when the determined difference between the loudness of the duckedfirst audio and the given dynamic range is less than the determinedloudness of the background noise, compressing the first audio to adynamic range that is louder than the determined loudness of thebackground noise and playing back the compressed first audio; and whenthe determined difference between the loudness of the ducked first audioand the given dynamic range is greater than the determined loudness ofthe background noise, playing back the first audio without compression.6. The playback device of claim 3, wherein determining the loudness ofbackground noise in the given environment comprises measuring theloudness of the background noise in the given environment via one ormore microphones.
 7. The playback device of claim 6, wherein at leastone of the one or more microphones is housed in a networked microphonedevice that is distinct from the playback device, and wherein measuringthe loudness of the background noise in the given environment via one ormore microphones comprises causing the networked microphone device tomeasure the loudness of the background noise in the given environment.8. The playback device of claim 7, wherein measuring the loudness of thebackground noise in the given environment comprises offsetting the firstaudio being played back by the playback device from the measurement ofthe background noise in the given environment.
 9. The playback device ofclaim 1, wherein playing back the ducked first audio concurrently withthe second audio comprises: detecting that a signal-to-noise ratiowithin the given environment is below a voice input threshold; andresponsively, filtering the first audio, wherein filtering the firstaudio comprises cutting the first audio in a frequency rangecorresponding to human speech.
 10. The playback device of claim 9,wherein filtering the first audio further comprises boosting the firstaudio outside the frequency range corresponding to human speech.
 11. Theplayback device of claim 1, wherein the playback device is a firstplayback device of a group of playback device that includes one or moresecond playback devices, and wherein playing back the ducked first audioconcurrently with the second audio comprises playing back the duckedfirst audio concurrently with the second audio in synchrony with the oneor more second playback devices.
 12. The playback device of claim 1,wherein the functions further comprise detecting that the spokenresponse to the voice input has been played back, and wherein duckingthe first audio comprises ducking the first audio until the spokenresponse to the voice input has been played back.
 13. The playbackdevice of claim 1, wherein sending, to the voice assistant, the recordedaudio in the buffer representing the voice input to the voice assistantcomprises sending, to one or more servers associated with the voiceassistant, the recorded audio in the buffer representing the voice inputto the voice assistant.
 14. A method to be performed by a playbackdevice, the method comprising: while playing back first audio in a givenenvironment at a given loudness via an audio stage and one or morespeakers: (a) recording, via one or more microphones, audio into abuffer; (b) detecting, within the recorded audio, a wake word to invokea voice assistant; (c) in response to detecting the wake word: (i)ducking the first audio while recording, into the buffer, audiorepresenting a voice input to the voice assistant and (ii) sending, tothe voice assistant, the recorded audio in the buffer representing thevoice input to the voice assistant; (d) receiving, from the voiceassistant in response to the voice input, second audio representing aspoken response to the voice input; and in response to receiving thesecond audio representing the spoken response to the voice input,ducking the first audio while playing back the ducked first audioconcurrently with the second audio representing the spoken response tothe voice input via the audio stage and the one or more speakers. 15.The method of claim 14, wherein ducking the first audio while recordingaudio representing the voice input to the voice assistant comprisesducking the first audio to a first volume level, and wherein ducking thefirst audio while playing back the ducked first audio concurrently withthe second audio representing the spoken response to the voice inputcomprises ducking the first audio to a second volume level that isdifferent from the first volume level.
 16. The method of claim 15,further comprising: determining a loudness of background noise in thegiven environment, and wherein ducking the first audio to the secondvolume level that is different from the first volume level comprisesducking the first audio to a particular volume level that is based onthe loudness of background noise in the given environment.
 17. Themethod of claim 16, wherein ducking the first audio to the particularvolume level that is based on the loudness of background noise in thegiven environment comprises ducking the first audio in proportion to adifference between the given loudness of the first audio and thedetermined loudness of the background noise.
 18. The method of claim 17,wherein playing back the ducked first audio concurrently with the secondaudio comprises: determining that a difference between a loudness of theducked first audio and a given dynamic range is (a) less than thedetermined loudness of the background noise or (b) greater than thedetermined loudness of the background noise; when the determineddifference between the loudness of the ducked first audio and the givendynamic range is less than the determined loudness of the backgroundnoise, compressing the first audio to a dynamic range that is louderthan the determined loudness of the background noise and playing backthe compressed first audio; and when the determined difference betweenthe loudness of the ducked first audio and the given dynamic range isgreater than the determined loudness of the background noise, playingback the first audio without compression.
 19. The method of claim 14,wherein sending, to the voice assistant, the recorded audio in thebuffer representing the voice input to the voice assistant comprisessending, to one or more servers associated with the voice assistant, therecorded audio in the buffer representing the voice input to the voiceassistant.
 20. A non-transitory, computer-readable medium having storedthereon instructions, that when executed by one or more processors of aplayback device, cause the playback device to perform functionscomprising: while playing back first audio in a given environment at agiven loudness via an audio stage and one or more speakers: (a)recording, via one or more microphones, audio into a buffer; (b)detecting, within the recorded audio, a wake word to invoke a voiceassistant; (c) in response to detecting the wake word: (i) ducking thefirst audio while recording, into the buffer, audio representing a voiceinput to the voice assistant and (ii) sending, to the voice assistant,the recorded audio in the buffer representing the voice input to thevoice assistant; (d) receiving, from the voice assistant in response tothe voice input, second audio representing a spoken response to thevoice input; and in response to receiving the second audio representingthe spoken response to the voice input, ducking the first audio whileplaying back the ducked first audio concurrently with the second audiorepresenting the spoken response to the voice input via the audio stageand the one or more speakers.